Feb. 2, 2017 - Lug loaders to date have traditionally either been hydraulic or pneumatic systems, but wood processing equipment supplier USNR has introduced a different take on the machine.

Its ElectraTong lug loader is all-electric. USNR’s engineering manager of its Salmon Arm, B.C. division, Thomas Congdon gave Canadian Forest Industries the details of this new system.

“One of the biggest things is, by being all-electric, you get away from the nuisances that come from hydraulics or pneumatics. You’re not worrying about leaks and it’s easier to maintain,” Congdon says. “The other thing with the all-electric is that we can set up parameters and a recipe. So at a push of a button, you can change from a recipe that’s aimed at a certain species of lumber or a certain wood diet.”

“If it’s a planer mill application, then it can be set up per batch of the product you’re producing,” he says. Congdon explains that the set up refers to timing points or when lumber is picked up and released, as well as how quickly lumber can be moved into the lug loader.

Congdon says those aspects make the ElectraTong more appealing to sawmillers because pneumatic and hydraulic systems don’t allow changing such specifications through a computer interface. “You have to go over and physically adjust things, so this way it can all be done through the control system,” he says.

“You can switch from a certain set up from one species of wood to another, or frozen wood and non-frozen wood; that type of thing. So there are a lot of advantages to the electric.”

Glen Sorenson is the maintenance manager at B.C.-based Gorman Bros. Lumber. He says the company is happy with their new ElectraTong lug loader.

“We’ve been able to move our operators from the lug loader [and] we’ve also increased our lug-per-minute rate through the line,” Sorenson says.

Congdon says the ElectraTong lug loader can run over 250 LPM in certain applications.

Gorman Bros.’ old lug loader ran off a hydraulic system.

Sorenson says installation of the ElectraTong went very well. “We did several pieces of equipment at the same time. We took out our hydraulic fence and installed the USNR fence. We also took out the scanner and put in [USNR’S] new scanner.”

Congdon says the electric system also allows for sensing how hard the board is being clamped. “We can do that through electrical feedback and load sensing. And therefore we can, on the fly, adjust how hard we are clamping the wood,” he says. “You don’t want to over-clamp it and mark it and you don’t want to under-clamp it and not grab the board well. So that’s something that can be set up as part of the electric recipe based on what you’re trying to do.”

Sorenson mentions two other differences Gorman Bros. noticed since the new installation. “We’re able to run the line at a higher speed and we’ve increased our piece count through the line as well,” Sorenson says.

He says the increased piece count and getting the operators away from the lug loader are the main changes with the new equipment, adding that the latter also makes operations safer.

Congdon says USNR has not experienced any issues with retrofitting the lug loader to certain space requirements.

“It fits in a similar footprint to other lug loaders. It does require a slight offset elevation, but we have a way to make that up and fit it into an existing level trim line space,” Congdon says.

“It’s gone very nicely in. All of our installations to date have been retrofit installations except for one. It was a stud mill in British Columbia, that was a new line,” he says.

As pleased as Gorman Bros. is with their new machine, Sorenson says there is one limitation. “What we do is we cut three-inch to 12-inch, so it is a challenge to deal back-to-back 12-inch pieces with three-inch mixed in,” he says. “And I don’t think we can get much higher at this point in piece count than where we are.”

“That said we haven’t been able to do what we’re doing now with our old lug loader,” Sorenson adds.

To date, four lug loaders have been installed in Canada and three in the U.S., but Congdon says six have now been sold in the U.S.

Congdon says the lug loader is for both sawmills and planer mills.

“In the planer mill application we can use a different gripping tong to not damage the wood. It’s for all types of products. It can do one-inch to over four-inch, stud mills, full dimension mills,” he says.

“Being a tong style lug loader, it’s very good at random widths and random thicknesses,” Congdon says. “The way we do backlog control is unique and we’re using our product called Mill Track, which is a camera-based system that looks down over top of the lug loader and lug load infeed, and then we control those backlog tables with the camera systems.”

Sorenson’s favourite aspect of the ElectraTong? “It’s tunable, the clamping pressure is adjustable; everything is just much more controlled with servos controlling the infeeds and the clamping… We’re happy with it.”CREDITS: